Utilization of Packers and other angular sealing type devices to seal annular spaces between tubular members have been employed in various industries for a relatively long period of time. One industry utilizing such seals is the hydrocarbon recovery industry, which generally utilizes many annular sealing devices (packers, etc.) for various purposes in the wellbore. While available, annular sealing devices work well for their intended purpose. A common consideration for the use of and selection of a type of annular seal is the risk of extrusion of the sealing element axially due to pressure differential across the seal. For this reason, the art has developed a number of different types of backup rings whose purpose is to reduce the radial dimension of the annulus between two tubular components so that extrusion gap is narrowed thereby making extrusion less likely.
Prior art backup elements generally rely upon conical components that are splayed open to a large diameter when compressed. This requires at least a stretchable, if not resilient property, to be retained in the material used as the backup. While such resilient properties enable these devices to function, they also are the Achilles' heel of the device because they do not provide sufficient rigidity to prevent extrusion of the primary seal in some conditions.
Other prior art elements utilize metal backup rings but they tend to be more complex requiring multiple petals or other interactive structures allowing them to attain a larger diametrical dimension upon axial compression. Such metal elements are more costly and have a relatively narrow adaptiveness and unexpected conditions at the point of use.
As the industry will continue to require backup rings for the foreseeable future to prevent primary element extrusion, the art will well receive an improved backup element.